Light-Induced Mott-Insulator-to-Metal Phase Transition in Ultrathin Intermediate-Spin Ferromagnetic Perovskite Ruthenates

Ruxin Liu; Liang Si; Wei Niu; Xu Zhang; Zhongqiang Chen; Changzheng Zhu; Wenzhuo Zhuang; Yongda Chen; Liqi Zhou; Chunchen Zhang; Peng Wang; Fengqi Song; Lin Tang; Yongbing Xu; Zhicheng Zhong; Rong Zhang; Xuefeng Wang

doi:10.1002/adma.202211612

Light-Induced Mott-Insulator-to-Metal Phase Transition in Ultrathin Intermediate-Spin Ferromagnetic Perovskite Ruthenates

Adv Mater. 2023 Mar;35(12):e2211612. doi: 10.1002/adma.202211612. Epub 2023 Feb 13.

Authors

Ruxin Liu¹, Liang Si^{2

3}, Wei Niu^{1

4}, Xu Zhang¹, Zhongqiang Chen¹, Changzheng Zhu¹, Wenzhuo Zhuang¹, Yongda Chen¹, Liqi Zhou⁵, Chunchen Zhang⁵, Peng Wang^{5

6}, Fengqi Song⁷, Lin Tang⁸, Yongbing Xu¹, Zhicheng Zhong⁹, Rong Zhang^{1

10}, Xuefeng Wang¹

Affiliations

¹ Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
² School of Physics, Northwest University, Xi'an, 710127, China.
³ Institute of Solid State Physics, Vienna University of Technology, Vienna, 1040, Austria.
⁴ School of Science, Nanjing University of Posts and Telecommunications, Nanjing, 210023, China.
⁵ College of Engineering and Applied Sciences, Nanjing University, Nanjing, 210093, China.
⁶ Department of Physics, University of Warwick, Coventry, CV4 7AL, UK.
⁷ School of Physics, Nanjing University, Nanjing, 210093, China.
⁸ Department of Physics, Tsinghua University, Beijing, 100084, China.
⁹ Key Laboratory of Magnetic Materials and Devices, Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences, Ningbo, 315201, China.
¹⁰ Department of Physics, Xiamen University, Xiamen, 316005, China.

PMID: 36626850
DOI: 10.1002/adma.202211612

Abstract

Light control of emergent quantum phenomena is a widely used external stimulus for quantum materials. Generally, perovskite strontium ruthenate SrRuO₃ has an itinerant ferromagnetism with a low-spin state. However, the phase of intermediate-spin (IS) ferromagnetic metallic state has never been seen. Here, by means of UV-light irradiation, a photocarrier-doping-induced Mott-insulator-to-metal phase transition is shown in a few atomic layers of perovskite IS ferromagnetic SrRuO_3- _δ . This new metastable IS metallic phase can be reversibly regulated due to the convenient photocharge transfer from SrTiO₃ substrates to SrRuO_3- _δ ultrathin films. These dynamical mean-field theory calculations further verify such photoinduced electronic phase transformation, owing to oxygen vacancies and orbital reconstruction. The optical manipulation of charge-transfer finesse is an alternative pathway toward discovering novel metastable phases in strongly correlated systems and facilitates potential light-controlled device applications in optoelectronics and spintronics.

Keywords: Mott insulators; charge transfer; ferromagnetism; insulator-to-metal transition; light illumination; ultrathin SrRuO 3.

Abstract

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